Process of preparing diphthaloylnaphthalene compounds and new compounds obtainable thereby



Patented July 11, 1933 UNITED STATES PATENT: OFFICE ARTHUR 'WOL'FRAM, on FRANKFoR'r-ON-THE 1uAIN-RQDELHEIM,,o Ann EMI-L' Haus- IDORFER, OF HOFHEIM IN' TAUNUS, GERMANY, ASSIGNORS TO GENERAL ANIL INE- WORKS, INC. 01? NEW YORK, N. Y., A-CORPORATION OF DELAWARE PROCESS OF PREPARING DIPHTHALOYLNAPHTI-IALENE COMPOUNDS 1 COMPOUNDS OBTAIN'ABLE THEREBY Ann NEW No Drawing. Application filed April 24, 1930, Serial No. 447,106, and in Germany May 3," 1929.

The present invention relatesto a process of preparing diphthaloylnaphthalene compounds and to new compounds obtainable thereby.

Our process comprises treating a compound of the general formula:

wherein 'X represents a cyano or carbo'xylic acid group and wherein the aromatic nuclei may be substituted with concentrated sulfuric acid as an acid condensing. agent. I When using mild conditions of reaction our process, yields compounds of the general formula: r

coon wherein the aromatic nuclei may be substituted. v p v j d When using stronger conditions of reaction the process .goes farther and compounds of the following general formula are obtainable; o

wherein the aromatic nucleimay be substituted. V

Weprefer to use as the acid condensing agent sulfuric acid which may have difierent degrees of concentration.

Under milder conditions of reaction we understand for instance a treatment of the reaction compounds in a sulfuric acid solution of about 75% strength while avoiding any heating above the boiling point. As stronger conditions of reaction we designate for instance the heating of the reaction mass ina'sulfuric acid of about 95-96% strength up to a temperature of about 150l60 G.

The new compounds obtainable by our'new process may be represented by the following general formula wherein either Y represents hydrogen in which case X stands forthe carboxylic acid group or Y and X represents jointly the group CO- and wherein the aromatic nuclei may be substituted.

The following examples illustrate the invention, but they are not intended to limit it thereto, the parts being by weight:

(1) 1 part of 2.2"-dinitrilo-1.5-dibenzoylnaphthalene, melting at 257 C. is dis-" solved in 10 parts of sulfuric acid of -96% strength. The solution thus ob.-

tained is heated for a short time to about 1 O. C. When diluting it with water;

the 1.2.5.G-diphthaloylnaphthalene precipi- .tates inthe form of yellow, metallically shino ing needles orlaminae. a

diben oyl-QQIQdicarboxylic f v 7 place. IIBy-treatingthis acid with sulfuric thus obtained is heated to boiling for a short,

time and diluted with Water. and there is obtained-the light yellow 2"-carboXybenzoylnaphthanthraquinonewhich di g l in a] k511i e rly colorless solution and yields With hydrosulfite a brown'Yab-jj The ring closure of W-carbo Xyben ZOyI- naplithanthraquinone into; :1 .2.-15,. 6;diphthaloylnaphthalene is effected by heating it in sulfuric acid or 95%' 96% strength to 160C, I (3-) By heating 2'2" -dinitrilo;l.5 -dibenzoylnaphthalene; in-;s ulfuric acid {of 7.5% strength to a temperature below .theboiling point, saponification 'into lb-naphthaleneacid :takes acid of 959% strength in a manner analogous to that of llxai rnple 1, there is likewise obtained 1.2.5.6rdiphthaloylnaphthalene.

-, (4) 1.5- na phthalenedibenzoyl-Qi.24f '-dicarboxylic' acid may be.condensed,just as 25,27 I I 'dinitrilo-l.5 dibenZoyl naphthalene,into {2'- carboxybenzoyl-naphthaiithraquinone and converted into 12.5.G-diphthalOylnaphthalens as described in Example 2.

(5) 1 partof 2:.2{"-dinitrilo-5'.5"dichlo- L r0-1.5-dibenioylsnaphthalene is dissolved in parts ofsulfuric acid-,of 82% strength. The solution thus obtained is heated to boiling for a short time. Qmdihitiofi With Water, there precipitates 1.2.5.6; (2'.2"-dichlorodiphthaloyl) -naphthalene of the following formula: s 7- The run -eai-aaaasualoyl) naphthalene dissolves-in concentrated sulfuric acid With a reddish orange coloration and is capable of yielding brown Vat.

' It melts attemperatures above 400 C.

We claim:

1. The process Whichcomprises heating a compound of the general formula:

wherein X' stands for the cyano orcarboxylic ,The process Whichcomprises heating a compound of the general formula:

wherein Xstands for the cyano or carboxylic acid group in the presence :of of about to 96% strength. 3. 'As-new. .products the compounds of the general formula Wherein-- either representsah didgii 'WlllCh: case X' sta-n'ds" for the carboxylic acid group or Y and X represent jointlyzzthe Chlorine. ,-v' TM" 11x ,1 4; As a new product, the compound of the formula: e,

group CO'- and Z represents hydrogen or acid groupin the presence, of: sulfuric acid.

sulfuric acid 5. As a new product the co a of he probable formula:

V 8. As a new product, the compound of the probable formula:

tures.

, 0 p p dissolving in alkali to a nearly colorless solution. 7 V p In testimony whereof, weafiix our signa- ARTHUR WOILFRAM. EMIL HAUSDORFER; 

